Determine the test statistic. A study investigated whether regular mammograms resulted in fewer deaths from breast cancer over a period of 20 years. Among 30,602 women who never had mammograms, 182 died of breast cancer, while only 166 of 30,290 who had undergone screening died of breast cancer. a) Do these results suggest that mammograms may be an effective screening tool to reduce breast cancer deaths? b) If your conclusion is incorrect, which type of error did you commit? z= (Round to two decimal places as needed.) -